Corkscrew



FIG. 1 is a front elevational view of my new design for a corkscrew;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side elevation thereof; and

FIG. 6 is a left side elevation thereof. 

The ornamental design for a corkscrew, as shown and described. 